I doubt these would infest books, they are a different type of psocod as I mentioned earlier, the 'booklice' are wingless. These are the outdoor type, they are likely to stay in the compost.
I had loads of them come inside on one of my walls when we had a very hard winter, they remained on a cool east facing wall so I left them. Come warmer weather they all disappeared, they are so small they would easily escape through a gap in the door.
They were the type in the photo on this article .. these live mainly under my Camellia leaves.
http://www.guardian-online.com...
